Jupiterimages/Thinkstock(NEW YORK) -- It's Monday morning and you're about to head out the door to go to work when you realize that your keys are missing.

In a panic, you search your whole house, turning over pillows, opening drawers and even checking the trash can, only to later find out that your keys were in your bag -- where they have been all along.

As frustrating as they can be, moments like these are pretty common and probably brought on by stress-induced memory loss.

ABC's Katie Couric spoke to Dr. Gayatri Devi about all these little lapses of memory we experience, how to prevent them and when they may be a sign of something more serious.

Devi, a neurologist and director of New York Memory and Healthy Aging Services, suggests that simple mind exercises can help, particularly ones that utilize a very different part of the brain than you're accustomed to using. If you sit at a computer analyzing data all day, do something physical or manual to wake up the rest of your brain.

Humans begin to experience memory loss at the early stages of childhood. It is necessary to forget things, Devi says, otherwise the memory would overflow like your inbox. Forgetting unnecessary pieces of information allows space in the memory for new and more pertinent material.

Aging also triggers some memory loss, and menopause can, as well. Women experiencing menopause may have trouble remembering names, words or where they placed things.

A healthy diet and keeping all aspects of the brain engaged are critical tools to keep one's memory sharp, but sleep is important, as well.

Devi also says that habits help alleviate memory loss by creating automatic response. For example, if you always put your car keys in your handbag, you'll know that's where they are even if you forget putting them there.